proxy support missing

[tdehesse]

module does not work for me behind a proxy (when ENV variables set for https_proxy etc)

fix:

$ diff -u /tmp/AnyEvent-SlackRTM-1.1/lib/AnyEvent/SlackRTM.pm lib/perl5/AnyEvent/SlackRTM.pm
--- /tmp/AnyEvent-SlackRTM-1.1/lib/AnyEvent/SlackRTM.pm 2019-10-04 05:01:17.000000000 +1000
+++ lib/perl5/AnyEvent/SlackRTM.pm      2020-11-26 14:41:42.432644470 +1100
@@ -45,6 +45,8 @@
         agent => "AnyEvent::SlackRTM/$VERSION",
     );

+    $furl->env_proxy();
+
     my $res = $furl->get($START_URL . '?token=' . $self->{token});
     my $start = try {
         decode_json($res->content);